The present invention relates generally to the field of reinforced concrete construction and in particular to reinforcing networks for concrete columns, beams, chimneys and the like structures.
Reinforced concrete construction techniques involve the strengthening of poured concrete structures by arranging reinforcing materials, usually a reinforcing frame of steel bars, within a form and causing concrete in the plastic state to solidify about the reinforcing materials. Reinforced concrete structures are much stronger and offer greater design latitude than those formed by other construction techniques. Consequently, reinforced concrete construction is suitable for columns, beams, chimneys and the like structures. In addition to longitudinally extending reinforcing bars for such structures the reinforcing network normally included helically wound wire or stirrups and tie wires for connecting them together. The function of the stirrups and tie wires was to hold the reinforcing members in a specific, geometrical relation to one another. This facilitates complex reinforcing frame constructions to produce one piece reinforced concrete structures with complex and relatively elongated shapes.
Many of the prior art devices for constructing reinforcing frames have limited application in complex structures requiring connection and support in several nonparallel planes and involving deformed reinforcing bars because they do not make quick, secure connections. Another problem ensued with columnar structures such as chimneys at large heights and the effectiveness of labor and manual dexterity at such heights. Another drawback of prior art devices is the fact that nominal movement may easily upset the alignment of an entire frame requiring adjustment before pouring concrete around it or resulting in a defective structure.
Another problem associated with such prior art devices is bleeding, that is, rust discoloration of a finished concrete surface caused by oxidation of the support device portions that rest against the form and ultimately at or near the finished surface of a concrete structure.